Write a function that will return a string of country codes from an argument that is a string of prices (containing dollar amounts following the country codes). Your function will take as an argument a string of prices like the following: "US$40, AU$89, JP$200". In this example, the function would return the string "US, AU, JP".

def get_country_codes(prices): # your code here

# don't include these tests in Vocareum from test import testEqual

testEqual(get_country_codes("NZ$300, KR$1200, DK$5"), "NZ, KR, DK") testEqual(get_country_codes("US$40, AU$89, JP$200"), "US, AU, JP") testEqual(get_country_codes("AU$23, NG$900, MX$200, BG$790, ES$2"), "AU, NG, MX, BG, ES") testEqual(get_country_codes("CA$40"), "CA")